<template>
    <div class="nav-bar" :class="{ 'is_fixed': isFixed }">
        <div class="container">
            <div class="pro-title">
                {{ title }}
            </div>
            <div class="pro-param">
                <a href="javascript:;">概述</a><span>|</span>
                <a href="javascript:;">参数</a><span>|</span>
                <a href="javascript:;">用户评价</a>
                <slot name="buy"></slot>
            </div>
        </div>
    </div>
</template>

<script>

export default {
    name: 'nav-bar',
    props:{
        title:String,
    },
    data() {
        return {
            isFixed: false
        }
    },
    mounted() {
        window.addEventListener('scroll', this.initHeight)
    },
    methods: {
        initHeight() {
            let scrollTop = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop
            this.isFixed = scrollTop > 152 ? true : false
        }
    },
    destroyed(){
        window.removeEventListener('scroll',this.initHeight,false)//false表示冒泡；true为捕获
    }
}
</script>

<style lang="scss">
@use './../assets/scss/config.scss' as *;
@use './../assets/scss/mixin.scss' as *;

.nav-bar {
    height: 70px;
    line-height: 70px;
    border-top: 1px solid $colorH;
    background-color: $colorG;
    z-index:10;
    &.is_fixed {
        position: fixed;
        top: 0;
        width: 100%;
        box-shadow: 0 5px 5px $colorE;
    }

    .container {
        @include flex();

        .pro-title {
            font-size: $colorH;
            color: $colorB;
            font-weight: bold;
        }

        .pro-param {
            font-size: $fontJ;

            span {
                margin: 0 10px
            }

            a {
                color: $colorC;
            }
        }
    }
}
</style>